Anti-ageing compounds discovered in roadside weed

The fruit of the cocklebur plant (Xanthium strumarium L), which is considered a weed, shows promise as a source of anti-ageing ingredients, according to researchers in Myongji University, South Korea.

The antioxidant and anti-inflammatory components in the spiky fruit could be useful as a skin protectant. In laboratory tests using cells and tissues, these compounds reduced damage from UVB exposure and sped wound healing in laboratory tests using cells and tissues. The cocklebur extracts also appear to influence the production of collagen, a protein that gives skin its elasticity and prevents wrinkles.

The spiky fruit of the cocklebur were found to contain antioxidant and anti-inflammatory components (Photo: Cocklebur © Felician Scorobete | Dreamstime.com)

"We found that cocklebur fruit has the potential to protect the skin and help enhance production of collagen," said Eunsu Song, a doctoral candidate at Myongji University in South Korea, who conducted the research with Myongji University Professsor Jinah Hwang. "In this regard, it could be an attractive ingredient for creams or other cosmetic forms. It will likely show a synergistic effect if it is mixed with other effective compounds, such as hyaluronic acid or retinoic acid, against aging."

Song presented the new research at Discover BMB, the annual meeting of the American Society for Biochemistry and Molecular Biology, held on March 25-28 in Seattle.

Found in Southern Europe, Central Asia and China, cocklebur thrives in moist or sandy areas such as roadside ditches and riverbanks. Using this weed for medicinal purposes is not new. Its distinctive fruits, covered in stiff husks and burrs, have been used for centuries in traditional medicines for headache, stuffy nose, disorders of skin pigmentation, tuberculosis-related illness and rheumatoid arthritis. In recent years scientists have explored its potential use in treatments for rheumatoid arthritis and cancer.

This new study however is the first to examine the fruit's properties as a wound-healing agent and skin protectant. Researchers first studied the molecular properties of cocklebur fruit extracts and isolated particular compounds that could contribute to anti-oxidant and anti-inflammatory effects. They then used cell cultures and a 3D tissue model with properties similar to human skin to study how these compounds affect collagen production, wound healing and damage from UVB radiation.

The results showed that the cocklebur fruit extracts encouraged collagen production, sped wound healing and exerted a protective effect against UVB radiation. Comparing the bioactivity of cocklebur fruits grown in different places, the researchers found that fruits grown in South Korea had slightly higher anti-oxidant and anti-inflammatory properties and greater wound-healing activity than those grown in China.

Researchers cautioned that high doses of cocklebur fruit extract can be harmful and further research is needed to determine how to use it safely in cosmetic or pharmaceutical applications.

"In its burrs, cocklebur fruit also has a toxic constituent, carboxyatractyloside, which can damage the liver," said Song. "Cocklebur showed a potential as a cosmetic agent by increasing collagen synthesis; however, it showed negative results with higher concentrations. Therefore, finding the proper concentration seems very important and would be key to commercializing cocklebur fruit extracts in cosmetics."

Moving forward, the researchers plan to further study the biological mechanisms involved and conduct experiments in animal alternatives to explore ways to safely adapt cocklebur fruit extracts for use in cosmetic products.